Armstrong Whitworth F.K.8
The Armstrong Whitworth F.K.8 was a British two-seat general-purpose biplane built by Armstrong Whitworth during the First World War. The type served alongside the better known R.E.8 until the end of the war, at which point 694 F.K.8s remained on RAF charge. Design and development The aircraft, originally designated the F.K.7, was designed by Dutch aircraft designer Frederick Koolhoven as a replacement for the Royal Aircraft Factory B.E.2c and the Armstrong Whitworth F.K.3. It was a sturdier aircraft than the F.K.3, with a larger fuselage and wings and was powered by a 160 hp (110 kW) Beardmore water-cooled engine.Bruce 1982, pp.100-101. The undercarriage used oleo shock absorbers and the observer was equipped with a Scarff ring mounting for a .303 in (7.7 mm) Lewis machine gun. No armament was initially provided for the pilot. The rudder featured a long, pointed horn-balance.Bruce 1982, pp. 100–101. The type was unusual in having dual controls, enabling the observer to control the aircraft in the event of the pilot becoming incapacitated by enemy action.Munson 1967, p. 31. The first example, A411, flew in May 1916 and was delivered to the Royal Flying Corps' Central Flying School at Upavon on 16 June. Because its rival, the Royal Aircraft Factory R.E.8 was still an unknown quantity, it was decided that 50 of the Armstrong Whitworth design, which was redesignated F.K.8., would be ordered for the RFC. The production aircraft which followed were identical in most respects to A411, with the addition of a forward-firing .303 in (7.7 mm) Vickers machine gun to port of and slightly behind the engine. The Armstrong Whitworth gun synchronising mechanism was incomplete at the time the first example A2636 had arrived in France and some early production F.K.8s may have used the Arsiad interrupter gear instead. The Armstrong Whitworth mechanism (like other early mechanical synchronising systems) proved unreliable and was later replaced by the Constantinescu gear.Bruce 1982, p. 101. From the fifth production aircraft the rudder balance was shortened and the shape of the vertical tailfin was modified.Bruce 1982, p. 102. F.K.8s had teething troubles, the oleo undercarriage was unable to withstand rough use on the frontline airfields, tailskids frequently broke and the original radiators blocked up quickly. Following instructions issued on 30 April 1917, some F.K.8s were refitted with simplified vee-undercarriages from Bristol F.2 Fighters. This soon led to a temporary shortage of these undercarriages and the practice had to be discontinued until May 1918, after which several F.K.8s were fitted with revised undercarriages.Bruce 1982, pp. 102–103. Most production F.K.8s had modifications to the wings, gunner's seat and the exhaust system. The tall inverted vee radiators incorporated improved tubes which reduced the blockages. On later aircraft the nose cowling was redesigned.,Bruce 1982, p. 103. and smaller box radiators were standardised. In service the F.K.8 (nicknamed the "Big Ack") proved to be effective and dependable, being used for reconnaissance, artillery spotting, ground-attack, contact-patrol and day and night bombing. It was reputedly easier to fly than the R.E.8, and was sturdier, but its performance was even more pedestrian, and it shared the inherent stability of the Royal Aircraft Factory types. While the pilot and observer were placed reasonably close together, communication between the two lacked the "tap on the shoulder" intimacy of the Bristol Fighter, or for that matter, the R.E.8. The F.K.13 seems to have been the designation of a reconnaissance version of the F.K.8 but it may have been a project.Bruce, J. M. [http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200618.html "Letter from J.M.Bruce to Flight, 15 May 1953, p. 612."] flightglobal.com, 15 May 1953. Retrieved: 7 December 2009. A total of 1,650 were built. Operational history The F.K.8 served with several squadrons on operations in France, Macedonia, Palestine and for home defence, proving more popular in service than its better known contemporary the R.E.8. The first squadron was 35 Squadron. The F.K.8 was principally used for corps reconnaissance but was also used for light bombing, being capable of carrying up to six 40 lb (20 kg) phosphorus smoke bombs, up to four 65 lb (29 kg) bombs or two 112 lb (51 kg) bombs on underwing racks.Mason 1994, p. 63. Two Victoria Crosses were won by pilots of F.K.8s; one by Second Lieutenant Alan Arnett McLeod of No. 2 Squadron RFC, on 27 March 1918 and the second by Captain Ferdinand Maurice Felix West of No. 8 Squadron RAF on 10 August 1918.Mason 1994, p. 64. With the R.E.8, the F.K.8 was scheduled to be replaced for corps reconnaissance by a version of the Bristol Fighter with a Sunbeam Arab engine. Unfortunately the engine was unsatisfactory and this version of the Bristol never saw service. Like the R.E.8, the F.K.8 was quickly discarded with the end of the war – the last squadron, No. 150 Squadron RAF, being disbanded at Kirec in Greece on 18 September 1919. One F.K.8 was purchased by a pilot named Sydney Stewart in the early 1920s. He took the aircraft to Buenos Aires and gave flying lessons. There he met Francisco Cusmanich, a Paraguayan pilot. Stewart and Cusmanich offered their services to the Paraguayan government during the Revolution of 1922. The F.K.8 was taken to Paraguay by ship. It received the name of "Presidente Ayala" in honor of the President of Paraguay at that time, Dr. Eusebio Ayala. Both pilots flew several reconnaissance and light bombing sorties over the rebel positions. In one of those sorties, the F.K.8 was hit several times with ground fire causing an explosion on board, killing Stewart and Cusmanich instantly.Klaus, Erich. "Paraguay Air Force." Aeroflight, 2 October 2008. Retrieved: 23 April 2009.English, Adrian J. ""La Guerra Civil Parguaya 1922-1923." Historia y Arqueologia Marítima. Retrieved: 23 April 2009. Civil service Eight aircraft were civil-registered after the war with two aircraft being used in Australia by the Queensland and Northern Territory Aerial Services (later QANTAS, then Qantas Airways Ltd.).Tapper 1988, pp. 67–68. Operators Civil operators ; *QANTAS Military operators ; :The Kingdom of Hejaz received two F.K.8s in 1921, at least one remaining in existence until 1923.Andersson Air Enthusiast July/August 2004, pp. 39–40. ; *Paraguayan Government *Paraguayan Air Force ; *Royal Flying Corps / Royal Air Force Western Front:Bruce 1982, pp. 103, 105. **2 Squadron RFC **8 Squadron RFC **10 Squadron RFC **35 Squadron RFC **82 Squadron RFC **Headquarters Communication Squadron RFC Home Defence: **36 Squadron RFC **39 Squadron RFC **50 Squadron RFC Macedonia: **17 Squadron RFC (part) **47 Squadron RFC (part) Palestine: **142 Squadron RFC Training:Bruce 1982, p.104. **3 Training Squadron RFC **15 Training Squadron RFC **31 Training Squadron RFC **39 Training Squadron RFC **50 Training Squadron RFC **57 Training Squadron RFC **61 Training Squadron RFC **110 Training Squadron RFC **127 Training Squadron RFC **1 Training Depot Station RFC Specifications (F.K.8) See also * F.K.3 *Royal Aircraft Factory B.E.2 *Royal Aircraft Factory R.E.8 *Rumpler C.I - *Breguet 14 References ;Notes ;Bibliography * Andersson, Lennart. "Wings Over the Desert: Aviation on the Arabian Peninsula: Part One Saudi Arabia". Air Enthusiast, No. 112, July/August 2004. pp. 39–43. ISSN 0143-5450. * Bruce, J.M. "The Aeroplanes of the Royal Flying Corps (Military Wing)." London: Putnam and Company, 1982. ISBN 0-370-30084-X. * Mason, Francis K. The British Bomber Since 1914. London: Putnam Aeronautical Books, 1994. ISBN 0-85177-861-5. * Munson, Kenneth. Aircraft of World War I. London: Ian Allan, 1967. ISBN 0-7110-0356-4. * Tapper, Oliver. Armstrong Whitworth Aircraft since 1913. London: Putnam, 1988. ISBN 0-85177-826-7. * Taylor, John W.R. "Armstrong Whitworth F.K.8." Combat Aircraft of the World from 1909 to the present. New York: G.P. Putnam's Sons, 1969. ISBN 0-425-03633-2. External links * Armstrong Whitworth F.K.8 Category:Single-engined tractor aircraft Category:Biplanes Category:1910s British bomber aircraft Category:1910s British military reconnaissance aircraft F.K.08 Category:Military aircraft of World War I Category:Qantas Category:Koolhoven aircraft